1. Field of the Invention
This disclosure relates to a signal processing device.
2. Description of the Related Art
For example, Patent Documents 1 to 3 disclose a signal processing device (a programmable logic device: PLD) which controls connection between a pair of nodes through a source and a drain of a pass transistor. In the signal processing device, the potential of a gate of the pass transistor is kept by turning off a transistor which uses an oxide semiconductor or the like. The transistor including an oxide semiconductor or the like can have extremely high off-state resistance. Therefore, in the signal processing device, the on/off state of the pass transistor can be maintained for a long time.